Alongside the Russians, the ESA is working with NASA on a project known as ExoMars (Exobiology in Mars), a similar but separate initiative to build nuclear-powered spaceships.

Although all of the above-mentioned entities are researching nuclear power for spacecraft, a spokesman for the Russian Federal Space Agency Roscosmos reiterated there was no collaborative agreement between the three agencies.

Roscosmos director Anatoly Perminov said the development of Megawatt-class nuclear space power systems (MCNSPS) would help Russia maintain a competitive edge in the space race for exploration of the moon and Mars.

The Russians are hoping to complete the nuclear engine design by 2012 at an estimated cost of 17 billion rubles ($600 million USD).

Still, it should be noted that ESA head Jean-Jacques Dorden recently confirmed the agency would "consider" using Russian experience and technology in its own nuclear-powered spacecraft developments.